With the rapid expansion of new energy, mining, metallurgy, and electroplating industries, nickel pollution in water bodies has become a growing threat to environmental quality and human health. During industrial processes, nickel ions often interact with various chemical additives to form highly stable heavy-metal organic complexes (HMCs). In nickel electroplating, for example, citrate (Cit) is widely used to improve coating uniformity and brightness, but the two carboxyl groups in Cit readily coordinate with Ni²⁺ to form Ni–Citrate (Ni-Cit) complexes (logβ = 6.86). These complexes significantly alter nickel’s charge, steric configuration, mobility, and ecological risks, while their stability makes them challenging to remove with conventional precipitation or adsorption methods. Currently, "complex dissociation" is regarded as the key step in removing HMCs. However, typical oxidation or chemical treatments suffer from high cost and complicated operation. Therefore, multifunctional materials with both oxidative and adsorptive capabilities offer a promising alternative. Researchers from Beihang University, led by Prof. Xiaomin Li and Prof. Wenhong Fan, used the CIQTEK scanning electron microscope (SEM) and electron paramagnetic resonance (EPR) spectrometer to conduct an in-depth investigation. They developed a new strategy using KOH-modified Arundo donax L. biochar to efficiently remove Ni-Cit from water. The modified biochar not only showed high removal efficiency but also enabled nickel recovery on the biochar surface. The study, titled “Removal of Nickel-Citrate by KOH-Modified Arundo donax L. Biochar: Critical Role of Persistent Free Radicals”, was recently published in Water Research.     Material Characterization Biochar was produced from Arundo donax leaves and impregnated with KOH at different mass ratios. SEM imaging (Fig. 1) revealed: The original biochar (BC) exhibited a disordered rod-like morphology. At a 1:1 KOH-to-biomass ratio (1KBC), an ordered honeycomb-like porous structure was formed. At ratios of 0.5:1 or 1.5:1, pores were underdeveloped or collapsed. BET analysis confirmed the highest surface area for 1KBC (574.2 m²/g), far exceeding other samples. SEM and BET characterization provided clear evidence that KOH modification dramatically enhances porosity and surface area—key factors for adsorption and redox reactivity.   Figure 1. Preparation and characterization of KOH-modified biochar.   Performance in Ni-Cit Removal Figure 2. (a) Removal efficiency of total Ni by different biochars; (b) TOC variation during Ni–Cit treatment; (c) Effect of Ni–Cit concentration on the removal efficiency of 1KBC; (d) Effect of pH on the removal performance of 1KBC; (e) Influence of coexisting ions on Ni–Cit removal by 1KBC; (f) Continuous-flow removal performance of Ni–Cit by 1KBC. (Ni–Cit = 50 mg/L, biochar dosage = 1 g/L)   Batch experiments de...

Aluminum alloys, prized for their exceptional strength-to-weight ratio, are ideal materials for automotive lightweighting. Resistance spot welding (RSW) remains the mainstream joining method for automotive body manufacturing. However, the high thermal and electrical conductivity of aluminum, combined with its surface oxide layer, requires welding currents far exceeding those used for steel. This accelerates copper electrode wear, leading to unstable weld quality, frequent electrode maintenance, and increased production costs. Extending electrode life while ensuring weld quality has become a critical technological bottleneck in the industry.   To address this challenge, Dr. Yang Shanglu's team at Shanghai Institute of Optics and Fine Mechanics conducted an in-depth study using the CIQTEK FESEM SEM5000. They innovatively designed a raised-ring electrode and systematically investigated the effect of ring number (0–4) on electrode morphology, revealing the intrinsic relationship between ring count, crystal defects in the weld nugget, and current distribution. Their results show that increasing the number of raised rings optimizes current distribution, improves thermal input efficiency, enlarges the weld nugget, and significantly extends electrode lifespan. Notably, the raised rings enhance oxide layer penetration, improving current flow while reducing pitting corrosion. This innovative electrode design provides a new technical approach for mitigating electrode wear and lays a theoretical and practical foundation for broader application of aluminum alloy RSW in the automotive industry. The study is published in the Journal of Materials Processing Tech. under the title “Investigating the Influence of Electrode Surface Morphology on Aluminum Alloy Resistance Spot Welding.” Raised-Ring Electrode Design Breakthrough Facing the electrode wear challenge, the team approached the problem from electrode morphology. They machined 0 to 4 concentric raised rings on the end face of conventional spherical electrodes, forming a novel Newton Ring electrode (NTR).   Figure 1. Surface morphology and cross-sectional profile of the electrodes used in the experiment   SEM Analysis Reveals Crystal Defects and Performance Enhancement How do raised rings influence welding performance? Using the CIQTEK FESEM SEM5000 and EBSD techniques, the team characterized the microstructure of weld nuggets in detail. They found that the raised rings pierce the aluminum oxide layer during welding, optimizing current distribution, influencing heat input, and promoting nugget growth. More importantly, the mechanical interaction between raised rings and molten metal significantly increases the density of crystal defects, such as geometrically necessary dislocations (GNDs) and low-angle grain boundaries (LAGBs), within the weld nugget. Optimal performance was observed with three raised rings (NTR3).   Figure 2. EBSD analysis of weld nugget microstruct...

Solid-state lithium metal batteries (SSLMBs) are widely recognized as the next-generation power source for electric vehicles and large-scale energy storage, offering high energy density and excellent safety. However, their commercialization has long been limited by the low ionic conductivity of solid electrolytes and poor interfacial stability at the solid–solid interface between electrodes and electrolytes. Despite significant progress in improving ionic conductivity, interfacial failure under high current density or low-temperature operation remains a major bottleneck. A research team led by Prof. Feiyu Kang, Prof. Yanbing He, Assoc. Prof. Wei Lü, and Asst. Prof. Tingzheng Hou from the Institute of Materials Research, Tsinghua Shenzhen International Graduate School (SIGS), in collaboration with Prof. Quanhong Yang from Tianjin University, has proposed a novel design concept of a ductile solid electrolyte interphase (SEI) to tackle this challenge. Their study, entitled “A ductile solid electrolyte interphase for solid-state batteries”, was recently published in Nature.     CIQTEK FE-SEM Enables High-Resolution Interface Characterization In this study, the research team utilized the CIQTEK Field Emission Scanning Electron Microscope (SEM4000X) for microstructural characterization of the solid–solid interface. CIQTEK’s FE-SEM provided high-resolution imaging and excellent surface contrast, enabling researchers to precisely observe the morphology evolution and interfacial integrity during electrochemical cycling.     Ductile SEI: A New Pathway Beyond the "Strength-Only" Paradigm Traditional inorganic-rich SEIs, though mechanically stiff, tend to suffer from brittle fracture during cycling, leading to lithium dendrite growth and poor interfacial kinetics. The Tsinghua team broke away from the “strength-only” paradigm by emphasizing “ductility” as a key design criterion for SEI materials. Using the Pugh’s ratio (B/G ≥ 1.75) as an indicator of ductility and AI-assisted screening, they identified silver sulfide (Ag₂S) and silver fluoride (AgF) as promising inorganic components with superior deformability and low lithium-ion diffusion barriers. Building on this concept, the researchers developed an organic–inorganic composite solid electrolyte containing AgNO₃ additives and Ag/LLZTO (Li₆.₇₅La₃Zr₁.₅Ta₀.₅O₁₂) fillers. During battery operation, an in-situ displacement reaction transformed the brittle Li₂S/LiF SEI components into ductile Ag₂S/AgF layers, forming a gradient “soft-outside, strong-inside” SEI structure. This multi-layered design effectively dissipates interfacial stress, maintains structural integrity under harsh conditions, and promotes uniform lithium deposition.   Figure 1. Schematic illustration of the component screening and functional mechanism of the ductile SEI during solid-state battery cycling.   Figure 2. Structur...

Recently, the 2025 Nobel Prize in Chemistry was awarded to Susumu Kitagawa, Richard Robson, and Omar Yaghi in recognition of “their development of metal–organic frameworks (MOFs).” The three laureates created molecular structures with enormous internal spaces, allowing gases and other chemical species to flow through them. These structures, known as Metal–Organic Frameworks (MOFs), have applications ranging from extracting water from desert air and capturing carbon dioxide, to storing toxic gases and catalyzing chemical reactions. Metal–Organic Frameworks (MOFs) are a class of crystalline porous materials formed by metal ions or clusters linked via organic ligands (Figure 1). Their structures can be envisioned as a three-dimensional network of “metal nodes + organic linkers,” combining the stability of inorganic materials with the design flexibility of organic chemistry. This versatile construction allows MOFs to be composed of almost any metal from the periodic table and a wide variety of ligands, such as carboxylates, imidazolates, or phosphonates, enabling precise control over pore size, polarity, and chemical environment.   Figure 1. Schematic of a Metal–Organic Framework   Since the first permanent-porosity MOFs appeared in the 1990s, thousands of structural frameworks have been developed, including classic examples like HKUST-1 and MIL-101. They exhibit ultrahigh specific surface areas and pore volumes, offering unique properties for gas adsorption, hydrogen storage, separation, catalysis, and even drug delivery. Some flexible MOFs can undergo reversible structural changes in response to adsorption or temperature, showing dynamic behaviors such as “breathing effects.” Thanks to their diversity, tunability, and functionalization, MOFs have become a core topic in porous materials research and provide a solid scientific foundation for studying adsorption performance and characterization methods.   MOFs Characterization The fundamental characterization of MOFs typically includes powder X-ray diffraction (PXRD) patterns to determine crystallinity and phase purity, and nitrogen (N₂) adsorption/desorption isotherms to validate the pore structure and calculate apparent surface area. Other commonly used complementary techniques include: Thermogravimetric Analysis (TGA): Evaluates thermal stability and can estimate pore volume in some cases. Water Stability Tests: Assesses structural stability in water and across different pH conditions. Scanning Electron Microscopy (SEM): Measures crystal size and morphology, and can be combined with energy-dispersive X-ray spectroscopy (EDS) for elemental composition and distribution. Nuclear Magnetic Resonance (NMR) Spectroscopy: Analyzes overall sample purity and can quantify ligand ratios in mixed-ligand MOFs. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES): Determines sample purity and elemental ratios. Diffuse Reflect...

With the acceleration of industrialization and the continuous growth of pollutant emissions, organic wastewater poses a serious threat to ecosystems and human health. Statistics show that energy consumption from industrial wastewater treatment accounts for 28% of global water treatment energy use. However, conventional Fenton technology suffers from catalyst deactivation, leading to low treatment efficiency. Metal-based catalysts in advanced oxidation processes face common bottlenecks: the redox cycling process cannot be effectively sustained, electron transfer pathways are restricted, and traditional preparation methods rely on high temperature and high pressure with yields of only 11–15%.   To address these challenges, a research team from Dalian University of Technology developed a Cu-C nanocatalyst by directionally coupling commercial cellulose with copper ions using a wet-chemical galvanic replacement method. They further established a novel degradation system featuring a dual-channel catalytic mechanism (radical pathway + direct electron transfer) and broad pH adaptability. The material achieved 65% tetracycline degradation within 5 minutes (vs. <5% by commercial catalysts), with copper ion leaching below 1.25 mg/L (lower than the national standard of 2.0 mg/L). In a packed-bed reactor (PTR), over 99% pollutant removal was achieved within a residence time of only 20 seconds. By enabling sustained catalytic activity through the direct electron transfer pathway, this approach overcame the long-standing issue of poor environmental adaptability in traditional catalysts.   The study, entitled “Robust dual-channel catalytic degradation relying on organic pollutants via Cu-C composites with directional electron harvest and classical radical species generation”, was published in Chemical Engineering Journal. Cu-C Nanocatalyst Formation Using commercial cellulose as the support, the team incorporated copper ions via a wet-chemical galvanic replacement method to construct Cu-C nanocomposites with dual-channel catalytic activity. Characterizations revealed unique electron transfer effects under various conditions. SEM imaging (CIQTEK SEM5000) revealed the microstructural evolution: pristine cellulose exhibited a disordered network, which, after composite formation, transformed into 10 nm copper spheres that self-assembled into 100 nm hierarchical aggregates. This structure ensured high dispersion and electron transport. SEM-EDS confirmed uniform element distribution. FTIR spectra revealed a Cu₂O peak at 682.31 cm⁻¹ due to redox reactions during synthesis. The presence of C=C, C=O, and C–H groups further supported the findings, while a strong –OH peak was observed at 3200–3600 cm⁻¹. XPS analysis indicated that Cu 2p signals were primarily from Cu₂(OH)₂CO₃ and Cu₂O, with C 1s showing C=C and C–C bonds, consistent with FTIR results.   Figure 1. Preparation and Characterization of the C...